Rev. D 12/11

7

PFS704-729EG

www.powerint.com

PI-5338-021711

~5 V

(full power)

~4.8 V

PFS704-716

PFS704-716

PFS704-716

PFS723-729

~5 V

~2.5 V

~1.25 V

~0.8 V

~170 VAC

~140 VAC

~5 V

~2.5 V

controlled with respect to the internal error-voltage level (output

power) to allow the converter to maintain output voltage

regulation and relatively flat conversion efficiency between 10%

to 100% of rated load which is essential to meet many efficiency

directives.

The degree of frequency slide is also controlled as a function of

peak input line voltage, at high input line the maximum off-time

voltage reference at zero error-voltage will be approximately 1/2

of the maximum value at low input line conditions.

The lower V

high input line operation.

Protection Modes

VOLTAGE MONITOR (V) Pin Shutdown

The VOLTAGE MONITOR pin features a shutdown protection

mode which can be used with the VOLTAGE MONITOR pin

resistor or external circuitry to cover system faults. During

start-up (1 V < V

VOLTAGE MONITOR pin exceeds the I

duration exceeding approximately (1 ms), the IC disables the

internal MOSFET for the entire duration that the V pin current is

above I

pin exceeds the I

the IC will reinitiate the start-up sequence.

Brown-In Protection (I

The VOLTAGE MONITOR pin features an input line undervoltage

detection to limit the minimum start-up voltage detected

through the V pin. This detection threshold will inhibit the

device from starting at very low input AC voltage.

Brown-Out Protection (I

The V pin features a brown-out protection mode wherein the

HiperPFS will turn-off when the V pin current is below the Line

UV-threshold for a period exceeding the t

the event a single half-line cycle is missing (normal operating

line frequency is 47 to 63 Hz) the brown-out protection will not

be activated. The HiperPFS shutdown in effect gradually

reduces the internal error-voltage to zero volts at rate of 1 V/ms

Figure 8.

(a) Frequency Variation Over Line Half-Cycle as a Function of Input Voltage (b) Frequency Variation Over Line Half-Cycle as a Function of Load.

Figure 9.

V

0

45

90

135

180

120

230 VAC

180 VAC

135 VAC

115 VAC

Peak Load

90 VAC

110

100

90

80

70

60

50

40

30

20

10

Line Conduction Angle (°C)

0

45

90

135

180

120

110

100

90

80

70

60

50

40

30

20

10

Line Conduction Angle (°C)

100% Peak Load

75% Peak Load

25% Peak Load

50% Peak Load

Expected Frequency

Range at Peak

Rated Load